U.S. patent application number 11/013681 was filed with the patent office on 2005-05-19 for non-hazardous oxidative neutralization of aldehydes.
Invention is credited to Zhu, Peter.
Application Number | 20050107631 11/013681 |
Document ID | / |
Family ID | 34576345 |
Filed Date | 2005-05-19 |
United States Patent
Application |
20050107631 |
Kind Code |
A1 |
Zhu, Peter |
May 19, 2005 |
Non-hazardous oxidative neutralization of aldehydes
Abstract
Methods, compositions, and devices for alleviating the problems
of toxic discharge of aldehydes present in waste streams are
disclosed. The methods relate to forming neutralized aldehydes by
treating aldehydes with oxidizing agents. The oxidizing agents
offer a simple, effective, fast and inexpensive solution for
treatment of toxic aldehydes prior to disposal into the
environment.
Inventors: |
Zhu, Peter; (Irvine,
CA) |
Correspondence
Address: |
PHILIP S. JOHNSON
JOHNSON & JOHNSON
ONE JOHNSON & JOHNSON PLAZA
NEW BRUNSWICK
NJ
08933-7003
US
|
Family ID: |
34576345 |
Appl. No.: |
11/013681 |
Filed: |
December 16, 2004 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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11013681 |
Dec 16, 2004 |
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10349363 |
Jan 22, 2003 |
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10349363 |
Jan 22, 2003 |
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09896589 |
Jun 29, 2001 |
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Current U.S.
Class: |
562/531 |
Current CPC
Class: |
A62D 3/36 20130101 |
Class at
Publication: |
562/531 |
International
Class: |
C07C 051/16; C07C
051/235 |
Claims
1. A system for neutralizing aldehydes and making the aldehydes
less toxic comprising: a) a container; b) a source of aldehyde
selected from the group consisting of o-phthalaldehyde,
glutaraldehyde, formaldehyde and mixtures thereof directed to the
container; and c) a source of oxidizing agent directed to the
container to yield treated aldehydes of lower toxicity than the
untreated aldehydes.
2. The system of claim 1, wherein the oxidizing agent is selected
from the group consisting of hydrogen peroxide, benzoyl peroxide,
peroxyformic acid, peroxyacetic acid, trifluoroperacetic acid,
peroxybenzoic acid, ammonium cerium nitrate, nitric acid, ammonium
nitrate, potassium chromate, sodium dichromate, potassium
dichromate, chlorine, sodium chlorate, sodium hypochlorite,
potassium hypochlorite, calcium hypochlorite, sodium hypobromite,
sodium hypoiodite, potassium hypoiodite, sodium iodate, periodic
acid, sodium periodate, potassium periodate, manganese dioxide,
potassium manganate, potassium permanganate, potassium persulfate,
magnesium permanganate, ruthenium tetroxide and mixtures
thereof.
3. The system of claim 1, wherein the oxidizing agent is hydrogen
peroxide.
4. The system of claim 3, wherein the hydrogen peroxide is in
solution form.
5. The system of claim 3, wherein the hydrogen peroxide is in solid
form.
6. The system of claim 1, wherein the oxidizing agent is potassium
persulfate.
7. The system of claim 1, wherein the oxidizing agent is sodium
hypochlorite.
8. The system of claim 14 further comprises a source of
diluent.
9. The system of any of the claims 1 to 8, wherein the sources
added to the container are controlled to achieve the treated
aldehydes having a toxicity level of LC.sub.50 greater than 500
mg/L.
Description
RELATED APPLICATIONS
[0001] This patent application is related to concurrently filed and
commonly assigned patent application U.S. Ser. No. 09/896,589,
filed Jun. 29, 2001 entitled "NON-HAZARDOUS BASIC NEUTRALIZATION OF
ALDEHYDES" (Attorney Doc. No. ASP-0028), the disclosure of which is
incorporated by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The invention relates to neutralization of aldehydes for the
purpose of complying with waste disposal requirements established
by federal and state environmental protection agencies, in
particular, with forming non-reversible neutralized aldehydes which
are non-hazardous and do not revert back to toxic aldehydes.
[0004] 2. Description of Related Art
[0005] Waste disposal of aldehydes has become increasingly more
difficult over the years. Treatment of wastes containing a certain
amount of aldehyde prior to placement of the waste into the
environment is required by law. The extent of such treatment may
vary depending upon the location of where the waste is generated
and the stringency of the environmental standards in that area. For
example, waste containing aldehyde may be classified as a hazardous
waste in California under 22 CAL. CODE REGS., TIT. 22, .sctn.
66696. Formaldehyde also may be considered a hazardous waste on the
federal level under 40 C.F.R. .sctn. 261.33(e) if it is a
commercial chemical product (e.g., pure technical grade
formaldehyde or formaldehyde is the sole active ingredient of the
product that is to be disposed). Every state has an environmental
regulation that is at least as stringent as this formaldehyde
standard. State regulations also may be more stringent than this
standard.
[0006] Additionally, facilities that discharge waste water to
Publicly Owned Treatment Works ("POTW") or directly into navigable
waters may be required to meet standards that are established by a
government agency. The standard may vary for each facility
depending upon the quality of the receiving water and the
concentration of aldehyde found in the waste water that is
discharged into the environment by industry in that area.
[0007] Waste containing aldehyde may be generated by a variety of
processes. For example, aldehydes such as glutaraldehyde and
o-phthalaldehyde ("OPA") are used in disinfecting medical devices
or instruments. Waste containing aldehydes also may be generated by
painting operations, stripping operations related to floors, or
other manufacturing operations.
[0008] Typically, ammonia and sodium bisulfite ("SBS") are used to
treat many aldehydes. These compounds, however, have not proven to
be effective at neutralizing OPA in accordance with environmental
regulations.
[0009] A waste is classified as a hazardous waste in California if
the waste being examined "has an acute aquatic 96-hour LC.sub.50
less than 500 milligrams per liter (mg/L) when measured in soft
water (total hardness 40 to 48 milligrams per liter of calcium
carbonate) with fathead minnows. . . . " 22 CAL. CODE REGS., TIT.
22, .sctn. 66696. LC.sub.50 represents the concentration of a waste
that is necessary to kill 50% of a particular animal exposed to a
waste.
[0010] Note that a nonhazardous waste is generally considered by
federal and state environmental agencies as a waste that does not
satisfy the criteria set forth in defining a hazardous waste.
Therefore, wastes generated in California that have a
LC.sub.50>500 mg/L are nonhazardous wastes and wastes having
LC.sub.50<500 mg/L are classified as hazardous. SBS, for
example, in combination with OPA, produces a product that is
generally considered hazardous under California environmental law
as shown in Table 1 by LC.sub.50 being consistently below 500 mg/L.
For this study, CIDEX.RTM. OPA (commercially available from
Advanced Sterilization Products.RTM., a Johnson & Johnson
Company of Irvine, Calif.) was used to supply the OPA.
1TABLE 1 Neutralization Of OPA Using SBS OPA Content LC.sub.50
Sample Type (%) (mg/L) Comments Fresh CIDEX .RTM. OPA at 0.3%
0.301% 31.1 mg/L 1 OPA Fresh CIDEX .RTM. OPA at 0.15% 0.158% 50.4
mg/L 2 OPA Reuse CIDEX .RTM. OPA at 0.3% 0.295% 31.1 mg/L 3 OPA
SBS/OPA = 4:1 N/A 68.3 mg/L 4 SBS/OPA = 2:1 N/A 46.3 mg/L 5 1.
Fresh CIDEX .RTM. OPA at 0.3% OPA was prepared by diluting the
fresh Cidex OPA solution with deionized water. 2. Fresh CIDEX .RTM.
OPA at 0.15% OPA was prepared by diluting the fresh Cidex OPA
solution with deionizedwater to the level of 0.15% of OPA. 3. Reuse
of CIDEX .RTM. OPA at 0.3% OPA was prepared by diluting the
simulated reuse CIDEX .RTM. OPA (14 days) with deionized water. 4.
SBS/OPA = 4:1, 10% SBS (10 mL) was combined with 100 mL of the
fresh CIDEX .RTM. OPA solution at 0.3% OPA (sample 1 above) at the
SBS/OPA molar ratio of 4 to 1 for 30 minutes, and then the combined
solution was used in the 22 CAL. CODE REGS., TIT. 22, .sctn. 66696
test for California. 5. SBS/OPA = 2:1, 10% SBS (5 mL) was combined
with or 100 mL of the fresh CIDEX .RTM. OPA solution at 0.3% OPA
(sample 1 above) at the SBS/OPA molar ratio of 2 to 1 for 30
minutes, and then the combined solution was used for the fish test
in the 22 CAL. CODE REGS., TIT. 22, .sctn. 66696 test for
California.
[0011] In addition to lacking the ability to effectively neutralize
OPA, ammonia and SBS are problematic since they may be harmful to
the environment.
[0012] FIG. 1 shows that when OPA is combined with SBS at the molar
ratio of SBS/OPA=4:0 for 30 minutes, OPA has been neutralized since
the OPA concentration is nondetectable in a high performance liquid
chromatography (HPLC) analysis method, which has detection limit
for OPA at 10 ppm. However, the end product is still classified as
a hazardous waste as shown in Table 1. Therefore, even though the
aldehyde is neutralized completely by a neutralizer, the end
product may still be a hazardous waste.
[0013] The purpose of this invention is to invent an effective,
non-hazardous, convenient and inexpensive neutralizer for
glutaraldehyde, o-phthalaldehyde (OPA) and/or other aldehydes.
Glutaraldehyde and o-phthalaldehyde are the main chemicals used in
industry and hospital for high-level disinfection. The
glutaraldehyde or o-phthalaldehyde needs to be neutralized after
use before disposal, however, at this point, there are only very
limited neutralization methods available. Commonly assigned patent
application U.S. Ser. No. 09/321,964, entitled "ALDEHYDE
NEUTRALIZER" suggests using amino acids such as glycine as
neutralizers. While use of glycine offers an inexpensive, fast and
non-hazardous solution to aldehyde neutralization, there are,
however, some problems with the amino acid neutralizer approach.
One problem is that Schiff's base solutions formed between
o-phthalaldehyde and glycine is black. In Japan, the general
feeling is that they do not like black color; therefore, hospitals
send their used solution to the waste treatment companies for
disposal, which is expensive. Another approach to the problem of
aldehyde neutralization is offered by commonly assigned and
co-pending patent application U.S. Ser. No. 09/747,230 entitled
"REDUCTIVE AMINATION FOR ALDEHYDE NEUTRALIZATION" which teaches the
reaction of aldehydes with amino acid neutralizers followed by
reduction of the resulting imines to form amino acids as final
environmentally friendly products. This method is best carried out
on solid supports and the solid waste is disposed after
application. In another approach, commonly assigned and copending
patent application U.S. Ser. No. 09/746,344, entitled, "DEVICE AND
METHOD OF USE FOR ALDEHYDE REMOVAL", discloses using polymeric
amines as scavengers to remove aldehydes from waste solutions.
Although this method removes both glutaraldehyde and
o-phthalaldehyde from the used disinfectant solution, the solid
waste still must be handled separately.
[0014] Thus different approaches to the challenge of aldehyde
neutralization are still needed for various situations. This
invention is intended to offer another approach relating to
neutralization of aldehydes as hereinafter described.
SUMMARY OF THE INVENTION
[0015] One embodiment of the invention relates to a method for
making a neutralized aldehyde of lessened toxicity comprising the
steps of:
[0016] a) providing an aldehyde; and
[0017] b) contacting the aldehyde with an effective amount of an
oxidizing agent to render the treated aldehyde as neutralized and
less toxic compared with the untreated aldehyde.
[0018] Another embodiment of the invention relates to a system for
neutralizing aldehydes and making the aldehydes less toxic
comprising:
[0019] a) a container;
[0020] b) a source of aldehyde selected from the group consisting
of o-phthalaldehyde, glutaraldehyde, formaldehyde and mixtures
thereof directed to the container; and
[0021] c) a source of oxidizing agent directed to the container to
yield treated aldehydes of lower toxicity than the untreated
aldehydes.
[0022] A major advantage of this invention is that it is a simple,
fast, inexpensive, and non-hazardous method to neutralize aldehyde
sterilization solutions. When hydrogen peroxide is used as the
oxidant, it safely turns to water. The end product of oxidation of
aldehydes are either colorless or lightly colored as opposed to
some of the dark colored products formed by amino acid
neutralization of aldehydes as explained above.
[0023] Additional features, embodiments, and benefits will be
evident in view of the figures and detailed description presented
below.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] The features, aspects, and advantages of the invention will
become more thoroughly apparent from the following detailed
description, appended claims, and accompanying drawings in
which:
[0025] FIG. 1 shows the ratio of SBS:OPA and the concentration of
OPA remaining in solution after 30 minutes from combining the
ingredients.
DETAILED DESCRIPTION OF THE INVENTION
[0026] The invention relates to methods and compositions
particularly useful for the environmentally friendly and
non-reversible neutralization of aldehydes present in waste
generated from sterilizing medical devices (e.g., scalpels,
scissors, endoscopes, etc.) or laboratory equipment (e.g.,
glassware) that have been exposed to microorganisms such as
bacteria. As used herein, the term non-reversible is intended to
refer to the substantial prevention of the neutralized aldehyde
(e.g., amino acid treated aldehyde) from reverting back to the
starting or unneutralized aldehyde. Sterilizing includes
disinfecting medical devices.
[0027] The neutralizer comprises oxidants. Suitable oxidants are
selected from the group consisting of hydrogen peroxide, benzoyl
peroxide, peroxyformic acid, peroxyacetic acid, trifluoroperacetic
acid, peroxybenzoic acid, ammonium cerium nitrate, nitric acid,
ammonium nitrate, potassium chromate, sodium dichromate, potassium
dichromate, chlorine, sodium chlorate, sodium hypochlorite,
potassium hypochlorite, calcium hypochlorite, sodium hypobromite,
sodium hypoiodite, potassium hypoiodite, sodium iodate, periodic
acid, sodium periodate, potassium periodate, manganese dioxide,
potassium manganate, potassium permanganate, potassium persulfate,
magnesium permanganate, ruthenium tetroxide and mixtures
thereof.
[0028] When the oxidant is used in solution form, suitable solvents
comprise water and alcohol. Suitable alcohols may include methanol,
ethanol, isopropanol, n-propanol, and butanol. Water or alcohol may
also contain acetone, acetonitrile, or tetrahydrofuran (THF).
[0029] Oxidants are an improvement over the typical chemicals such
as ammonia or sodium bisulfite used to neutralize aldehydes since
the oxidants quickly and effectively neutralize aldehydes to a
level prescribed by federal and state environmental agencies.
Effective amounts of the oxidant to the aldehydes will vary based
on the aldehyde being neutralized and the oxidizer used.
[0030] In the case of glutaraldehyde as the aldehyde and hydrogen
peroxide as the oxidizer, nonhazardous neutralization will occur
when the molar ratio range of glutaraldehyde to hydrogen peroxide
is typically at least about 1: 1, typically from about 1:1 to
1:100; preferably from 1:4 to 1:50, and most preferably from 1:8 to
1:16. In the case of glutaraldehyde and sodium hypochlorite as the
oxidizer, nonhazardous neutralization will occur when the molar
ratio range of glutaradehyde to sodium hypochlorite is typically
about at least 1:1.5, typically from about 1:1.5 to 1:100;
preferably from 1:2 to 1:50, and most preferably from 1:3 to
1:16.
[0031] In the case of o-phthalaldehyde as the aldehyde and hydrogen
peroxide as the oxidizer, nonhazardous neutralization will occur
when the molar ratio range of o-phthalaldehyde to hydrogen peroxide
is typically at least about 1:0.7, typically from about 1:0.7 to
1:100; preferably from 1:1 to 1:10, and most preferably from 1:1.4
to 1:7. In the case of o-phthalaldehyde and sodium hypochlorite as
the oxidizer, nonhazardous neutralization will occur when the molar
ratio range of o-phthalaldehyde to sodium hypochlorite is typically
at least about 1:06, typically from about 1:0.6 to 1:50; preferably
from 1:0.8 to 1:5, and most preferably from 1:1 to 1:2. In the case
of o-phthalaldehyde and potassium persulfate as the oxidizer,
nonhazardous neutralization will occur when the molar ratio range
of o-phthalaldehyde to potassium persulfate is typically at least
about 1:8, typically from about 1:8 to 1:100; preferably from 1:9
to 1:50; and most preferably from 1:10 to 1:25.
[0032] To neutralize aldehydes, the oxidizer in solution or in
solid form may be added to waste water that is in a tank (e.g., a
neutralization tank at a waste water treatment plant), or in a
small container (e.g., a bucket) where aldehydes must be
neutralized before they are placed into a sewer system that may
discharge to a POTW or into navigable waters. Solids contaminated
with aldehydes (e.g., dirt, rags, or gloves, etc.) may be
neutralized by directly adding the neutralizer to the solids or by
placing the solids into a container with the neutralizer and,
optionally, water.
[0033] Thus another embodiment of the invention relates to a system
for neutralizing aldehydes and making the aldehydes less toxic
comprising:
[0034] a) a container;
[0035] b) a source of aldehyde selected from the group consisting
of o-phthalaldehyde, glutaraldehyde, formaldehyde and mixtures
thereof directed to the container; and
[0036] c) a source of oxidizing agent directed to the container to
yield treated aldehydes of lower toxicity than the untreated
aldehydes.
[0037] Additionally the system may further comprise a source of a
pH adjusting material to adjust the pH of the treated aldehyde.
[0038] The source of materials suitable for use in conjunction with
the systems of this invention are the same as disclosed above in
the discussion relating to the methods of this invention.
Additionally, the system may contain controls on any of the sources
added to the container to achieve the treated aldehyde having a
LC.sub.50 greater than 500 mg/L or any other desired non-toxicity
level.
EXAMPLES
[0039] Unless specified, all the reactions were performed at room
temperature and concentrations are expressed on a w/v % basis
except as noted and except when reference is made to 0.55% (w/w %)
OPA from CIDEX.RTM. OPA Solution and 2.4% (w/w %) glutaraldehyde
from CIDEX.RTM. Glutaraldehyde wherein these solution as expressed
on a weight to weight basis.
[0040] Two methods were used to evaluate the extent of
neutralization. The first method is the thin layer chromatography
visualization ("TLC visualization") method. In general, the TLC
visualization method comprises the following steps: (a) spotting a
sample of the solution on the bottom of a TLC plate (usually silica
plate), (b) placing the TLC plate in a solvent chamber with the
plate side spotted with sample at the bottom. The solvent (usually
mixed solvents) is selected so that all the components in the
sample mixture is developed into isolated spots after developing
(c) developing (letting the solvent climbing the TLC plate) and
letting the mixture being pushed upward and separated into isolated
spots (d) visualization (to show the separated spot visually with
the aid of displaying agent, or fluorescence etc.). In the case of
the method used in the following examples, if aldehdye was present,
spots (or bands) would display a blue color with pink background
upon dipping in Schiff's reagent (Fluka 84655, diluted to 10%
concentration with ethanol).
[0041] The second method used was based on the visual examination
of color of the solution ("Color visualization"). Glycine solution
(1%) was used to detect the presence of OPA. The appearance of any
green color or dark green or black green is a good indication of
the presence of OPA. If only one aldehyde group was present (if the
other reacted with an oxidant), other color would display upon
adding glycine, such as yellow, yellowish orange or orange or even
reddish colors. Although the darkness of the green-flavored color
of the Schiff's base formed between glycine and OPA is good
indication of OPA level, one have to keep in mind that the Schiff's
base could be oxidized by many oxidants to cause darker color.
Caution must be taken where comparison is needed in these
situations. Although HPLC analysis is an ultimate tool for the
analysis of di-aldehyde remaining, we found that the above
estimation is quite sufficient for our purpose.
[0042] (A) Neutralization of Glutaraldehyde (Examples 1-8)
Example 1
[0043] To 0.5 mL of 2.4% glutaraldehyde, 0.5mL of 59% hydrogen
peroxide was added at room temperature. Immediately after mixing,
the resulting solution was tested by: (a) the TLC visualization
method using 1% glycine, with the results not showing any green or
green to dark color in a period of 1 hour; and (b) a drop of
Schiff's reagent (Fluka) test solution was added, no positive
results (no pink or purple color) was observed. Therefore, under
the test conditions, the oxidant, hydrogen peroxide, is effective
in neutralizing the glutaraldehyde.
Example 2
[0044] Into 6 beakers (50 mL) indicated below as 2-1 through 2-6, 1
mL 10% hydrogen peroxide was added, glutaraldehyde (2.4%) of
different volumes, 24.53, 12.27, 6.13, 3.07, 1.53, 0.77 mL
respectively, were added to beakers #2-1 through 2-6, respectively.
The solutions were shaken briefly and let stand for 2 hours.
Different amounts of water were added to the beakers to make them
to same volumes (25.53 mL). The solutions were spotted onto a TLC
silica plate on plastic (Aldrich) and dried in an oven at
75.degree. C. for 3 minutes and developed in an ethanol: methylene
chloride (1:4) solution. The plates were briefly dipped in Schiff's
reagent (Fluka) (diluted to 10% with ethanol) and heated in an oven
(75.degree. C.) for 5 minutes to visualize (blue spots with pink
background). The oxidant to aldehyde mole ratio and volume ratio
are summarized in Table 2. Vial "R" was 2.4% glutaraldehyde used as
reference. Results indicated that, under the test conditions, 2
volumes of 10% H.sub.2O.sub.2 is effective to neutralize 3 volumes
of 2.4% glutaraldehyde.
2TABLE 2 Effect of Hydrogen Peroxide (10%) and Glutaraldehyde
(2.4%) Mixing Ratio Exp. # 2-1 2-2 2-3 2-4 2-5 2-6 R Vol (10%
H.sub.2O.sub.2):Vol 1:25 1:12 1:6 1:3 1:1.5 1:0.77 Ref. (2.4%
Glutaraldehyde) H.sub.2O.sub.2:Glutaraldehyde 1:2 1:1 2:1 4:1 8:1
16:1 Mole Ratio TLC visualization Spot size decreases No spot from
exp. 1 to 4 No (All smaller than glutaraldehyde reference spot)
Some left glutaraldehyde left
Example 3
[0045] From Example 2, the solution of 2-2 (hydrogen
peroxide:glutaraldehyde volume ratio 1:12 and mole ratio 1:1) was
used. After mixing of 10% hydrogen peroxide (1 mL) and 2.4%
glutaraldehyde (12.27 mL), ImL of the mixed solution was mixed with
0.2 mL 1N sodium hydroxide solution. After standing at room
temperature overnight, no glutaraldehyde was left based on the TLC
result (same TLC condition). Adding base helped the oxidation.
Example 4
[0046] Same as in Example 3, but 0.2 mL 10% hydrochloric acid was
used instead of sodium hydroxide. Glutaraldehyde level did not
significantly drop after standing at room temperature overnight as
seen from TLC result. Adding acid did not significantly promote the
oxidation.
Example 5
[0047] To 1.0 mL of glutaraldehyde (2.4%) (un-activated), 0.5 mL
household bleach (5% NaOCl) was added and the solution gradually
turned yellow. The oxidation reaction was followed by TLC
visualization at 5 minutes and 20 minutes. The solutions were
spotted onto a TLC silica plate on plastic (Aldrich) and was blown
with air for 1 minute before developing in an ethanol: methylene
chloride (5:95(V/V)) solution. The plates were briefly dipped in
Schiff's reagent (Fluka) (diluted to 10% with ethanol) and heated
in an oven (75.degree. C.) for 5 minutes to visualize blue spots
with a pink background indicating glutaraldehyde was still present.
Most of the glutaraldehyde was not oxidized in 5 minutes while
almost all the glutaraldehyde was oxidized in 20 minutes.
Example 6
[0048] To 6 vials (2 mL) indicated below as 6-1 through 6-6, 100,
200, 350, 500, 650 and 800 .mu.L bleach (5% sodium hypochlorite)
were added respectively. Glutaraldehyde (2.4%) of different
volumes, 900, 800, 650, 500, 350 and 200 .mu.L were added to
beakers 6-1 through 6-6, respectively (Table 3). The solutions were
shaken briefly and allowed to stand for 20 minutes. The solutions
were spotted onto TLC silica plate on plastic (Aldrich) and was
blown with air for 1 minute before being developed in an ethanol:
methylene chloride (5:95(V/V)) solution. The plates were dipped in
Schiff's reagent (Fluka) (diluted to 10% with ethanol) briefly and
heated in oven (75.degree. C.) for 5 minutes to visualize blue
spots with pink background. Vial "R" was 2.4% glutaraldehyde
control. The colors of solutions indicate the amount of oxidation
which has taken place. The levels of the blue spots on the TLC
plate indicate the relative remaining of un-oxidized or
un-neutralized glutaraldehyde. The results indicated equal volumes
of bleach (5% NaOCl) can effective neutralize 2.4% glutaraldehyde
in 20 minutes.
3TABLE 3 Effect of Bleach (5% NaOCl) and Glutaraldehyde (2.4%)
Mixing Ratio Exp. # 6-1 6-2 6-3 6-4 6-5 6-6 R 5% NaOCl (.mu.L) 100
200 350 500 650 800 Ref. 2.4% Glut.(.mu.L) 900 800 650 500 350 200
Glutaldehyde NaOCl:Glut. 0.31:1 0.70:1 1.51:1 2.8:1 5.2:1 11.2:1
Mole Ratio TLC Most Some Little No Visualization glutaraldehyde
glutaraldehyde glutaraldehyde glutaraldehyde left left left
left
Example 7
[0049] The same experiment in Example 6 was repeated with the aid
of additional base. The added base slightly promotes the
glutaraldehyde oxidation (from the darker colors in Vials 6-2, 6-3
and 6-4 solutions and a little lighter colors of the corresponding
blue TLC spots).
4TABLE 4 Same as Table 3 with Additional Base (20 minutes reaction
time). Exp. # 6-1 6-2 6-3 6-4 6-5 6-6 R 5% NaOCl (.mu.L) 100 200
350 500 650 800 Ref. 1N NaOH (.mu.L) 10 10 10 10 10 10 Glut 2.4%
Glut (.mu.L) 900 800 650 500 350 200 NaOCl:NaOH:Glut 0.31:0.046:1
0.70:0.052:1 1.51:0.064:1 2.802:0.083:1 5.20:0.12:1 11.2:0.21:1
Mole Ratio TLC Most Some Little No visualization glutaraldehyde
glutaraldehyde glutaraldehyde glutaraldehyde left left left
left
Example 8
[0050] The same experiment in Example 7 was repeated with longer
reaction time (6 hours instead of 20 minutes). It was found that no
further oxidation occurred beyond the levels in that of Example 7.
This is an important finding that it supports that the oxidation of
glutaraldehyde is fast. Although the reaction time is important
during the first 20 minutes, it appears no longer important after
that. On the other hand, the amount of the oxidants, such as bleach
or hydrogen peroxide, is crucial.
5TABLE 5 Same as Table 4 with Extended Time (6 hours instead of 20
minutes) Exp. # 6-1 6-2 6-3 6-4 6-5 6-6 R 5% NaOCl (.mu.L) 100 200
350 500 650 800 Ref. 1N NaOH (.mu.L) 10 10 10 10 10 10
Glutaraldehyde 2.4% Glut (.mu.L) 900 800 650 500 350 200
NaOCl:NaOH:Glut 0.31:0.046:1 0.70:0.052:1 1.51:0.064:1
2.802:0.083:1 5.20:0.12:1 11.2:0.21:1 Mole Ratio TLC Most Some
Little No Visualization glutaraldehyde glutaraldehyde
glutaraldehyde glutaraldehyde left left left left
[0051] (B) Neutralization of OPA (Examples 9 -13)
Example 9
[0052] In 6 vials (2 mL) indicated below as 9-1 through 9-6, 100,
200, 350, 500, 650 and 800 .mu.L of hydrogen peroxide (10% hydrogen
peroxide) was added respectively, OPA (0.55%) of different volumes,
900, 800, 650, 500, 350 and 200 .mu.L were added to beakers 9-1
through 9-6, respectively (Table 6). The solutions were shaken
briefly and allowed to stand for 20 minutes. The solutions were
spotted onto TLC silica plate on plastic (Aldrich) and was blown
with air for I minute before developing in an ethanol: methylene
chloride (5:95(V/V)) solution. The plates were briefly dipped in
Schiff's reagent (Fluka) (diluted to 10% with ethanol) and heated
in an oven (75.degree. C.) for 5 minutes for visualization to
determine if any spotting resulted (to see black spots with pink
background). Only the reference OPA showed a black spot. To further
confirm this result, 200 .mu.L 1.0% glycine was added into each
vial and the color visualized in 5 minutes. Only the reference OPA
gave a green-black color and all the others do not show a color.
One may question if hydrogen peroxide would destroy the Schiff's
base and therefore its color. To confirm this, to 0.5 mL of the
Schiff's base solution (obtained from mixing the reference 1.0 mL
of 0.55% OPA with 200 .mu.L 1.0% glycine at room temperature for 5
minutes), 500 .mu.L 10% hydrogen peroxide was added and mixed. The
resulting color was even darker. Therefore, the above method is
valid (Schiff's base was not destroyed by hydrogen peroxide).
6TABLE 6 Oxidation of 0.55% OPA with 10% Hydrogen Peroxide Exp. #
9-1 9-2 9-3 9-4 9-5 9-6 R 10% H.sub.2O.sub.2 (.mu.L) 100 200 350
500 650 800 Ref. 0.55% OPA (.mu.L) 900 800 650 500 350 200 OPA
H.sub.2O.sub.2:OPA Mole Ratio 8.0:1 17.9:1 38.6:1 71.7:1 133.2:1
286.8:1 TLC Visualization No OPA left (No TLC black spot) Color
Visualization after No OPA left (No dark-green color of Schiff's
base) Mixing w/1% Glycine
Example 10
[0053] Oxidation of 0.55% OPA with 10% Hydrogen Peroxide (Less
Amount of Oxidant).
[0054] What is the minimum amount of hydrogen peroxide needed to
neutralize per volume of 0.55% OPA? Example 9 was repeated using
much less amount of hydrogen peroxide (Table 7). The same procedure
was followed. After addition of glycine, only the Vial 9-6 showed
dark green color, i.e., there was OPA not neutralized in this vial.
OPA in all the other vials were all neutralized. The results
indicated that only 2% volume of 10% hydrogen peroxide can be used
to effectively neutralize 0.55% OPA. The volume of hydrogen
peroxide can be reduced with more concentrated hydrogen peroxide
solution.
7TABLE 7 Neutralization of 0.55% OPA with 10% Hydrogen Peroxide
(With less oxidant) Exp. # 9-1 9-2 9-3 9-4 9-5 9-6 R 10%
H.sub.2O.sub.2 (.mu.L) 100 80 60 40 20 10 Ref. 0.55% OPA (.mu.L)
1000 1000 1000 1000 1000 1000 OPA H.sub.2O.sub.2:OPA Mole Ratio
7.171:1 5.737:1 4.302:1 2.868:1 1.434:1 0.717:1 Color Visualization
after No OPA left Little Mixing w/1% Glycine (No dark-green color
of Schiff's base) OPA left
Example 11
[0055] The similar experiment as that for Example 6 (except color
visualization was used instead of TLC visualization) was conducted
with 5% potassium persulfate as the oxidant (Aldrich 37,982-4, lot
21028BN) and OPA as the aldehyde (Table 8).
8TABLE 8 Oxidation of 0.55% OPA with 5% Potassium Persulfate Exp. #
6-1 6-2 6-3 6-4 6-5 6-6 R 5% K.sub.2S.sub.2O.sub.8 (.mu.L): 100 200
350 500 650 800 Ref. 0.55% OPA (.mu.L) 900 800 650 500 350 200 OPA
K.sub.2S.sub.2O.sub.8:OPA Mole 0.501:1 1.128:1 2.430:1 4.512:1
8.380:1 18.049:1 Ratio Color Visualization after Some OPA left
Little No OPA Mixing w/1% Glycine OPA left left
Example 12
[0056] Oxidation of 0.55% OPA with Bleach (5% Sodium Hypochlorite)
The similar experiment as that for Example 6 (except TLC was not
used) was conducted with household bleach 5% sodium hypochlorite
and OPA as the aldehyde (Table 9). It could be concluded that
oxidation was complete in all the vials. Based on this data, the
bleach amount could be further reduced.
9TABLE 9 Oxidation of 0.55% OPA with Household Bleach (5% sodium
hypochlorite) Exp. # 6-1 6-2 6-3 6-4 6-5 6-6 R 5% NaOCl (.mu.L) 100
200 350 500 650 800 Ref. 1N NaOH (.mu.L) 10 10 10 10 10 10 OPA
0.55% OPA (.mu.L) 900 800 650 500 350 200 NaOCl:NaOH:OPA
1.820:0.271:1 4.096:0.305:1 8.822:0.375:1 16.383:0.375:1
30.425:0.488:1 65.532:0.697:1 Mole Ratio Color Visualization No OPA
left after Mixing w/1% Glycine
Example 13
[0057] Oxidation of 0.55% OPA with Bleach (5% Sodium Hypochlorite)
(Less Amount of Oxidant).
[0058] Example 12 was repeated using much less amount of bleach and
the results are shown in Table 10. The same procedure was followed.
After addition of glycine for 5 minutes, only the Vials 6-5 and 6-6
showed a dark green color, i.e., there was OPA not neutralized in
these 2 vials. Based on our understanding of OPA/Glycine Schiff's
base color behaviors, we know there was only trace amount of OPA
un-neutralized in the Vial 6-4. Thus, based on Vial 6-3, about 6%
volume bleach (5% sodium hypochlorite) can be used to neutralize of
0.55% OPA. This is a very desired result considering the
inexpensive price of household bleach and the absence of concern of
disposing bleach to the drain. If 10-13% sodium hypochlorite was
used, only 3% volume will be needed.
10TABLE 10 Oxidation of OPA (0.55%) with Bleach (5% Sodium
Hypochlorite) (With less oxidant). Exp. # 6-1 6-2 6-3 6-4 6-5 6-6 R
5% NaOCl (.mu.L) 100 80 60 40 20 10 Ref. 0.55% OPA (.mu.L) 1000
1000 1000 1000 1000 1000 OPA NaOCl:OPA Mole 1.638:1 1.311:1 0.983:1
0.655:1 0.328:1 0.164:1 Ratio Color Visualization after No OPA left
Little OPA Some OPA left Mixing w/1% Glycine left
[0059] (C) Fish Tests
Example 14
[0060] Fish Tests
[0061] CALIFORNIA CODE REGS ("CCR") Title 22-Fathead Minnow
Hazardous Waste Screen Bioassay.
[0062] The following tests were conducted to determine whether
aldehydes neutralized by the oxidant, hydrogen operoxide, was
hazardous under the Californian regulation except that a more
stringent concentration of 750 mg/L was used instead of the 500
mg/L concentration of the Californian regulation.
[0063] (a) Hydrogen peroxide (5%) failed fish test (0% survival at
750mg/L concentration in 48 hours).
[0064] (b) OPA (125 mL, 0.55%) and hydrogen peroxide (25 mL, 5.0%)
were mixed thoroughly and waited for 20 minutes before fish test.
The mole ratio of OPA to H.sub.2O.sub.2 is 1 to 7.2. Test results
indicated that 2 out of the 10 fish died in 48hours (80% survival)
and 4 out of the 10 fish died in 96 hours (60% survival). Thus,
this composition would surpass the less stringent Californian
regulations.
[0065] (c) OPA (250 mL, 0.55%) and hydrogen peroxide (83.3 mL,
3.0%) were mixed thoroughly and waited for 20 minutes before fish
test. The mole ratio of OPA to H.sub.2O.sub.2 is 1 to 7.2. The
results indicated that all fish survived the challenge (100%
survival in 750 mg/L concentration after 96 hours) and exceeded the
Californian regulations.
[0066] In the preceding detailed description, the invention is
described with reference to specific embodiments thereof. It will,
however, be evident that various modifications and changes may be
made thereto without departing from the broader spirit and scope of
the invention as set forth in the claims. The specification and
drawings are, accordingly, to be regarded in an illustrative rather
than a restrictive sense.
* * * * *